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Biomedical subjects

J Martínek

Publications and source records attributed to J Martínek.

At least 19 recordsLinked to original sources
PubMed1994

Preparation of functionally active immobilized and perfused mammalian cells: an example of the hepatocyte bioreactor.

In the present study, a method has been employed for hepatocyte immobilization in agarose threads which allows for cell perfusion. The rat hepatocytes are isolated from the liver. A 1.8% low-gelling agarose solution is prepared in warm Krebs-Henseleit solution. The agarose solution is mixed 1:1 with the hepatocytes and the cells are immobilized in agarose threads by extruding the agarose-cell mixture through cooled Chemfluor teflon (TFE) tubing. Light and electron microscopy studies indicated the integrity of the hepatocytes in the gel matrix. This system allows for liver cell perfusion and viability studies to be carried out non-invasively on the cells and provides data that are comparable to those obtained with a perfused isolated liver. Immobilized hepatocytes are an in vitro system worthy of further evaluation which may be useful in the studies of liver cell metabolism and the response of the liver to foreign chemicals.

Animals↗
PubMed1994

Adrenergic lipolysis in immobilized and perfused adipocytes.

The method of cellular immobilization and perfusion was applied to adipocytes. The lipolytic effect of isoprenaline, whose action is produced as a result of receptor-drug interaction, was followed. An agarose solution kept at at 37 degrees C was mixed 1:1 with the cell suspension. Thereafter, adipocytes were immobilized in the agarose threads. The lipolytic effect of 0.1 ml of isoprenaline (1 x 10(-4) mol/l), that was rapidly introduced to the cell perfusion inlet in a non-recirculating system, was monitored by assessing glycerol production. The immobilized and perfused adipocytes exhibited significant lipolytic activity. After reaching the maximum effect, 0.1 ml of propranolol (1 x 10(-3) mol/l) that was applied to the bioreactor inlet, abolished the isoprenaline effect. The present data demonstrate the potential applicability of immobilized perfused adipocytes for various kinds of studies.

Adipocytes↗
PubMed1993

Use of mild periodic acid-thiosemicarbazide-silver proteinate staining for ultrahistochemical demonstration of glycoconjugates in the human uterine epithelium.

The human uterine epithelium has been studied by means of mild (0.1, 0.01% respectively) periodic acid (PA) oxidation followed by thiosemicarbazide-silver proteinate staining. Distribution of silver deposits provided evidence for glycoconjugates and was in the case of oxidation with 0.01% PA selective for sialic acid (N-acetylneuraminic acid) complexes. The electron dense silver particles were detectable at the outer side of apical plasma membranes and on the inner surface of lysosomal membranes. Also the marginal zone of lipid droplets reacted regularly. Since the lower concentration of PA proves sialogycoconjugates selectively, the positive staining depicted not only those in the membrane compartments but also as a layer between the hydrophobic content and the hydrophilic cytoplasm. In the granular endoplasmic reticulum of the individual microvillous cells a special glycoprotein of paracrystalline organisation was detected. The functional significance of this substance remains unclear. Nuclear channel systems (NCS) are frequently observed in the epithelial cells in the uterine glands. Similar staining properties of the NCS and nuclear envelope support the hypothesis of its nuclear origin.

Endometrium↗
PubMed1993

The changes in the myocardium under experimental conditions.

An effect of different interventions on the electron microscopic structure and morphometric parameters of the myocardium were studied. Application of cyclophosphamide and isoprenaline in the experimental animals allows the similar changes of mitochondrial partial volume like hypoxic periods of cardiac surgery by coronary bypass operation. Although the initial agents are different, the primary affected structures are sarcoplasm and mitochondria, whose proportions change promptly. The primary effect may be connected with alteration of membrane permeability caused by increased osmotic active ion transport on responsibility of the inhibited Na, K-ATP-ases (or F0 F1-ATP-ases irreversibly altered in mitochondria). The morphometric evaluation confirms not only statistically significant differences among the experimental groups treated by cyclophosphamide, isoprenaline and by cardioplegic ischaemic periods in the human myocardium but also by application of physiological saline in the control groups. Comparing the morphometric evaluation by manual processing with computer mediated image analysis we can conclude that the results correspond upon conditions of the specific defined raster for Weibel's intersection test only.

Adult↗
PubMed1993

Morphometrical histochemical and biochemical parameters in the dog alloxan diabetes.

Changes of morphometrical, biochemical, histochemical and immunohistochemical parameters were investigated in the alloxan diabetes in the dog. Samplings of material for electron microscopical and histochemical examinations were performed in 3 month period (4 times). A significant thickening of capillary basement membranes in the striated muscle (vastus lateralis) was ascertained even in the dog with glucose intolerance only. In this mentioned case a decrease of glucoso-6-phosphatase activity was observed. Evaluation of different types of muscle fibres assigned an increase of slow twitch fibres or intermediate ones respectively.

Animals↗
PubMed1991

A morphometric analysis of the capillary basement membrane as a diagnostic parameter in diabetes mellitus.

Thirty-seven diabetic patients were examined by a morphometric analysis of the basement membrane at submicroscopic level. According to how long they had had diabetes they were divided into three groups (A less than 2 years, B less than 15 years, C greater than 15 years) and the BM thicknesses measured were compared with the data obtained in five control subjects. Simultaneous biochemical and clinical screening was used to elaborate a Spearman's non-parametric correlating coefficient. The results confirmed that morphometric evaluation of the state of the capillary BM in skeletal muscle can be employed as a marker of organic complications in diabetes mellitus.

Adult↗
PubMed1990

Cardioprotective conditioning with glucose and insulin prior to cardiac surgery involving ischaemic cold arrest.

The study describes cardioprotective conditioning by means of high doses of glucose together with insulin and potassium. Eighteen hours before cardiac surgery, nine patients received continuous infusion of 1000 ml of 40% glucose solution along with 112 U of insulin and 60 mmol of potassium. Before and after ischaemic cold arrest, the myocardial a--v differences of lactate, pyruvate, glucose, Na, K, Cl, Ca, P, free fatty acids and triglycerides were analysed in all patients. Blood collections were performed in parallel with ultramicroscopy of biopsy specimens from the right atrium. The results were compared with those obtained in a control group of 22 patients without cardioprotective conditioning with glucose, insulin and potassium. Neither the analysis of the myocardial a--v differences of metabolites, nor the finding on the mitochondria and myofibrils documented statistically significant differences between the control and conditioned groups. Following termination of ischaemic cold arrest, patients in the conditioned group exhibited more glycogen grains in myocardial cells than those in the control group. While 34% of patients in the control group were defibrillated after revascularization, it was not necessary in any of the conditioned patients.

Adult↗
PubMed1990

[A regional health care information system used in the support of management].

The District Institute of National Health in Benesov uses automation of information oriented above all on therapeutic and preventive care. At present analyses on the assembled information are under way and are compared with the structure of analyses needed for the management of the health services. The first stage deals with the structure of dispensarized diseases which will be published by the authors.

Czechoslovakia↗
PubMed1989

Immunofluorescence detection of porcine anti-zona pellucida antibodies in sera of infertile women.

Fifty three samples of blood sera of women from infertile couples were investigated for presence of antibodies to zona pellucida. Using the immunofluorescence test, antibodies reacting with porcine zona pellucida could be detected in sera of women with unexplained infertility and also in the sera of a control fertile group. In most cases these antibodies could be adsorbed by porcine erythrocytes, indicating that the erythrocyte-like antigens are present in the porcine zona pellucida, as was confirmed by electron microscopic studies.

Animals↗
PubMed1989

[Metabolic and ultrastructural changes in the myocardium during heart arrest in patients undergoing surgery for ischemic heart disease].

The authors give an account of metabolic changes in the ultrastructure of the myocardium which develop during cardioplegic arrest of the heart muscle by cold during aortocoronary reconstruction operations. Using the technique of arteriovenous differences before myocardial ischemia and after its termination, the assessed differences in arterial blood and blood from the sinus coronarius as regards the blood sugar level, lactate, pyruvate, potassium, phosphorus, unsaturated fatty acids and triglycerides. The results revealed a marked disorder of the carbohydrate and ion metabolism and severe impairment of the ultrastructure of the heart muscle during cardiac arrest.

Adult↗